Durable resinous antistatic textile finish



United States Patent 3,503,795 DURABLE RESINOUS ANTISTATIC TEXTILEFINISH Tsai Hsiang Chao, Somerville, N.J., assignor to American CyanamidCompany, Stamford, Conn., a corporation of Maine No Drawing. Filed May4, 1967, Ser. No. 635,999 Int. Cl. D06m 11/00 US. Cl. 117-1395 9 ClaimsABSTRACT OF THE DISCLOSURE This invention relates to a durableantistatic textile finish produced by reacting a condensate of apolyamine with a halohydrin ether of a polyalkylene polyhydric alcoholwith N,N'-methylenebis(acrylamide) and to the process of applying thefinish to a synthetic hydrophobic textile material and to the textilematerial prepared by said application.

This invention relates to a durable, antistatic textile finish. Moreparticularly it relates to a durable antistatic finish for hydrophobictextile materials, a method of applying the finish to such materials andto the materials thus treated.

In general, textile fibers, yarns and fabrics made from synthetichydrophobic materials, as for example the nylons, the acrylic fibers,the polyester fibers, acetate fibers and the like, becomeelectrostatically charged whenever and wherever friction is applied tothem. Therefore many disadvantages are encountered during the millprocessing and fabricating and more so during the end use of thematerials manufactured. Aside from the discomfort to the individualwearing a garment which accumulates static electricity, there is alsothe serious problem of the attraction of dust and dirt particles whichresults in the garment having a soiled appearance. This usually causesfrequent launderings or dry cleanings resulting in poor fabric life dueto degradation caused by detergents and bleaches and the normal abrasionresulting from such processing.

The elimination of the static electricity in fabrics would ease themanufacturers problems, give more comfort to the consumer, and addgreater life to the textile materials. It would also reduce hazardousconditions found in such places as operating rooms or in other placeswhere ignition from static electricity could be dangerous.

Antistatic treatments of hydrophobic textile materials subject to theaccumulation of static electricity are not new and have been employed bymany in the past. However, many of these treatments have markeddisadvantages; typical of these are the following: complicated methodsof application, inability to be applied from aqueous media,incompatibility with other chemicals, poor durability andsoil-retentiveness of the finish applied when subjected to washing ordry cleaning, discoloration of the fabric, and loss of fabric strengthor odor problems during pressing.

Typical commercially available antistatic agents exhibit wet-soilindices of 42, 27, and 20, for example, using untreated nylon fabric asa standard index of 1.0. High wet-soiling index is a major reason whymany antistatic finishes, which are otherwise satisfactory, are notpresently in common commercial use.

In the ever increasing field of man-made fibers subject to theaccumulation of static electricity, there is a genuine need for a good,durable antistatic treatment which when properly applied will not impartany important deleterious side effects upon the textile materialfinished therewith or cause discomfort to the consumer.

Accordingly, it is an object of the present invention to provide anantistatic finishing composition which, when 3,503,795 Patented Mar. 31,1970 applied to synthetic hydrophobic textile materials subject to theaccumulation of static electricity, will impart thereto a durableantistatic finish.

A further object of the invention is to provide an antistatic finishcapable of application in a conventional straightforward manner from anaqueous medium and which is compatible and stable with other textileagents and auxiliaries.

It is a still further object of the present invention to provide anantistatic finish which does not discolor fabrics finished therewith,does not reduce fabric strength, and does not result in odor problemsduring pressing or upon completion of finishing.

Another object of this invention is to provide an antistatic finishhaving a high degree of durability to washing and dry cleaning, etc.

Another object is to provide an antistatic finish having a desirably lowaffinity for soil.

These and other objects of this invention will become apparent as thedescription thereof proceeds.

In my copending application Ser. No. 439,996, filed Mar. 15, 1965, nowPatent No. 3,411,945 is disclosed an antistatic finish for textilesprepared by reacting a polyalkylene glycol-polyamine resin with cyanuricchloride. This finish has good antistatic properties and is durable tolaundering, but is not so durable to dry cleaning. Moreover, cyanuricchloride, being an acid chloride, is unstable (hydrolyses in presence ofmoisture), is ditficult to handle, and has a pungent odor, thuspresenting problems in the manufacture of the antistatic agent.

It has now been discovered that an improved antistatic agent fortextiles can be obtained by reacting a polyalkylene glycol-polyamineresin with N,N'-methylenebis- (acrylamide) (Formula I).

The antistatic finish of this invention has good antistatic properties,is durable to laundering and dry cleaning and is free of disagreeableodor. Furthermore, the problems presented in using the unstable,odiferous cyanuric chloride as disclosed in my copending applicationSer. No. 439,996, have been unexpectedly eliminated by the use of thestable, non-odiferous, N,N'-methylenebis- (acrylamide) The polyalkyleneglycol-polyamine resins utilized in the reaction withN,N'-methylenebis(acrylamide) in this invention are the reaction productof one or more halo hydrin ethers reacted with one or more polyamines.Halohydrin ethers suitable as reactants include halohydrin ethers ofpolyalkylene polyhydric alcohols.

Halohydrin ethers with which this invention is concerned are generallyprepared from polyalcohols by the use of an epihalohydrin, the processbeing well known. The preferred epihalohydrin is the chloro-compoundepichlorohydrin. Other epihalohydrins are epibromohydrin andepiiodohydrin.

Condensation catalysts are used in reacting an epihalohydrin with apolyalcohol for the formation of a polyhalohydrin ether. Typicalcatalysts are those of the Lewis acid type, including anhydrous AlClZnCl SnCl and complexes such as the well-known BF etherates, etc., andthe Bronstead acid type, including HF, H and the like. Concentration ofthe catalysts may be varied from 0.1 percent to 2.0 percent dependingupon the individual catalysts. A reaction temperature between about 70C. and about 80 C. is recommended when boron trifluoride etherate isused as the catalyst.

Suitable polyalcohols include the preferred polyethylene glycols withaverage molecular weights between about 200 [and about 2,000, butmolecular weights between about 500 and about 1,000 are preferred.Although it is preferred to use about 2 moles of epihalohydrin per moleof polyethylene glycol, between 1 mole and 3 moles may be used. If 2moles of epihalohydrin are employed, the resulting halohydrin ether is amixture of products, but the predominant product is believed to be ofthe typical structural formula shown below:

OH OH XCH2-(EHCH2O(-CH2-CH2O)uCH2-( 3HGHzX where X is a halogen, andwhere n is an integer larger than zero.

Examples of other polyalcohols are: polypropylene glycols, andpolytrimethylene glycols.

The polyamine reactant includes amines having two or more primary orsecondary amino groups on separate carbon atoms, for example:trialkylenetetramines, such as triethylenetetramine; ethylenediamine;propylenediamine; hexamethylenediamine; trimethylenediamine;tetramethylene diamine; tetraethylenepentamine; 'diethylenetriamine;dipropylenetriamine; etc.

The amines suitable for use in this invention are represented by thefollowing typical formula:

Where m and it each represent an integer larger than zero.

To form the polyalkylene glycol-polyamine antistatic resin, by reactionof halohydrin ether and amine, the reaction temperature may range fromabout 65 C. to about 135 C. The preferred temperature range, which givesan antistatic agent having superior antistatic properties, ranges fromabout 80 C. to about 100 C. Although it is not necessary to employ asolvent for the reaction of halohydrin ether and amine, it is desirableto use a solvent such as alcohol, dioxane and especially water.

In carrying out the reaction of the halohydrin ether and the polyamine,the polyamine is added to the halohydrin ether, and the exothermicreaction is controlled by the rate of addition. In the reaction of theamine with the polyhalohydrin ether, an amine-hydrohalide salt isformed. This amine salt is then desirably reacted with an inorganicalkali to neutralize the hydrogen halide. Suitable alkalies arecarbonates or bicarbonates of alkali metals, for example, sodiumbicarbonate, sodium carbonate, potassium carbonate, potassiumbicarbonate, etc., and one equivalent, or less, of alkali per halohydringroup is generally used. Moreover, the alkali can be added at the startof the reaction.

In the reaction of a polyalkylene glycol-polyamine resin withN,N'-methylenebis(acrylamide) the reactants are mixed under essentiallyneutral conditions and the reaction is continued until a homogeneouscomposition is obtained indicating completion of the reaction.

The polyalkylene glycol-polyamine resin does not have to be isolatedbefore reacting with N,N'-methylenebis (acrylamide). The pH of the resinis adjusted to slightly below 7.0 by adding s-ufiicient acid, such asacetic acid, to neutralize sodium carbonate present. The amount ofN,N'methylenebis(acrylamide) used is between 5% and 25%, preferablybetween and 20%, based on the weight of the polyalkyleneglycol-polyamine resin. It 'is advantageous to add theN,N-methylenebis(acrylamide) as a slurry in water. The reaction iscarried out at a temperature between 50 and 90 0, preferably between 70and 80 C. The reaction mixture may be diluted with water to the desired.content of antistatic agent. For storage stability, it is desirable toadjust the pH of the finished antistatic agent to between 5 and 6 withan acid such as acetic acid.

In the preferred process for the novel antistatic resin of thisinvention, polyethylene glycol with average molecular weight of 600 isreacted with 2.2 moles of epichlorhydrin per mole of polyethylene glycolin the presence of a catalytic amount of boron trifluoride-etherate. Theepichlorhydrin is added slowly to the mixture of polyethylene glycol andcatalyst at a temperature between about 70 C. to about 75 C., whilecooling externally. To this reaction mixture, sodium'carbonate is added,and the mixture is boiled to destroy the catalyst and to remove traceamounts of the more volatile materials. About 10% oftriethylenetetramine, based on the weight of the halohydrin etherproduct present is added slowly at a temperature of between about C. toabout 100 C. Glacial acetic acid is then added to give a pH slightlybelow 7. After the evolution of carbon dioxide ceases, a suspension ofN,N'- methylenebis(acrylamide) (about 10% based on the weight of thepolyalkylene glycol polyamine component) in water is added at atemperature of about 70 C. After a further period of reaction, thehomogeneous solution is treated with glacial acetic acid to obtain a pHof about 5.5. The yield of active ingredient is considered to bequantitative.

The synthetic hydrophobic textile materials which may be treated withthe products of this invention include synthetic materials such asnylon, acetate rayon, acrylic fibers, and terephthalic acid-ethyleneglycol condensation products, for example. Any synthetic product whichcharacteristically accumulates static electricity is the type ofmaterial on which the antistatic agent of this invention may beadvantageously applied. The materials may be in the form of woven ornon-woven goods, tufted and pile fabrics, knitted goods, felted goodsand fibers both staple and filament. Applications can be made bypadding, spraying, or any appropriate means. The finishes areconveniently applied from an aqueous bath.

Applications for the products of this invention may be made underslightly acidic, neutral or alkaline conditions in a range between aboutpH 6 and about pH 11.0. The preferred pH range is between pH 9 and pH10.

Between about 0.25% and about 5.0% O.W.F., preferably between about 0.5%and about 2.0%, of the products of this invention is applied to thefabrics. The treated textile materials are normally dried byconventional methods, e.g., at about 225 F. for 1-2 minutes. If desired,the treated textile materials can be heated at higher temperatures forshort periods of time, but this is not required.

The following specific examples are Set forth to illustrate theinvention and are not intended to be limitative.

In the following examples, the parts and percentages are by weight.

EXAMPLE I To an anhydrous mixture at 70-75 C. of 225 parts (0.375 mole)of polyethylene glycol (average molecular weight 600), and 0.5 partboron trifluoride catalyst, introduced as a solution in about one partof ether, there was added over a period of about one hour 77 parts(0.825 mole) of epichlorohydrin. The reaction mixture was maintained ata temperature of 7075 C. for about 2.5 hours, adding 0.5 part of borontrifluoride as a solution is about 0.5 part of ether after the first 30minutes.

To the resulting mixture at about 55 C., there was added a solution of20.7 parts of sodium carbonate in 47 parts of water. The solution washeated rapidly to boil and held at this temperature for 10 minutesfollowed by cooling to 90-95 C. There was then added dropwise 28.15parts of triethylenetetramine in about a 15 minute period. Afterstirring the mixture at -97 C. for 30 minutes, 23.5 parts of glacialacetic acid was slowly added. After cooling to 70 C., a slurry of 29.6parts of N,N'- methylenebis(acrylamide) in 210 parts of water was added.Stirring was continued at 60 C. for about 45 minutes until a homogeneoussolution was obtained. Another 30 parts of glacial acetic acid wasadded, resulting in a pH of about 5.5 for the solution.

EXAMPLE II The antistatic agent of Example I was applied to nylontafi'eta by standard padding procedure at 2% solids on the weight of thefabric (O.W.F.) from an aqueous pad bath of pH 9.5 (sodium carbonate).The fabric was dried L 5 at 225 F. for 1.5 minutes and then heated at300 F. for 8 minutes.

The antistatic activity was measured by a procedure based on StandardTest Method 76-1959 of the American Association of Textile Chemists andColorists. Before the electrical resistivity of the fabric was measured,the fabric was conditioned in the testing chamber at 70 F. and 30%relative humidity. Resistivity values below 500 10 ohms indicate goodantistatic activities; resistivity values below 100x10 ohms indicateexcellent antistatic activities.

The washes were carried out in a home-type automatic washing machineusing a s nthetic detergent and the washing cycle recommended fordelicate fabrics. After the launderings, the antistatic tests wererepeated.

The dry cleanings were carried out by contacting a sample of the fabricwith a commercial fabric cleaning solvent containing a dry cleaningdetergent.

The results are shown in Table I.

TABLE I.-ANTISTATIO ACTIVITY [(Ohms X10 warp] Fabric Initial 10 washes40 washes 3 dry cleanings Untreated 100 50, 000 50,000 50, 000 Treated0. 1 0. 6 2. 6. Treated 0. 1 1. 5 2. 7 50, 000

Product of Example II of copending application Serial No. 439,996 forcomparison, which is prepared as follows:

To an anhydrous mixture of 450 parts (0.75 mole) of polyethylene glycol(average molecular weight 600) and 1.0 part of boron trifiuoridecatalyst, introduced as a solution in about 2 parts of ether, at 70-750. there was added over a period of about one hour 153 parts (1.65moles) of epichlorohydrin. The reaction mixture was maintained at atemperature of 70-75 C. for about 2.5 hours, adding 0.5 part of borontrifiuoridc as a solution in about 1 part ether after the first 30minutes.

To the mixture at about 5060 C. there were added about 05 parts of Waterand 41.4 parts of sodium carbonate. After boiling the mixture for 10minutes, 56.3 parts (0.385 mole) of triethylene tetramine was added overabout minutes at a temperature of 90-95" C. This temperature wasmaintained for about 30 minutes followed immediately by the addition of50 parts of glacial acetic acid. The product solution or dispersion wasadjusted to contain about 46% of active components.

When the evolution of carbon dioxide had ceased, the reaction mixturewas cooled to between 30 and 35 0., and a solution of 59.2 parts (0.325mole) of cyanuric chloride in 110 parts of dioxane was added slowly at30 35 C. After an additional reaction period of 30 minutes, 100 parts ofwater were added, followed by about 30 parts glacial acetic acid to givea pH of 4.0 or lower. The product solution or dispersion contained about46% of active component.

EXAMPLE III The aqueous pad baths (A and B) were prepared containing theproduct of Example I. The pH of each of the two pad baths was adjustedby adding sodium carbonate. The baths were applied to nylon taffeta by astandard padding procedure. The fabrics, containing 2% O.W.F. of theactive component of the product of Example I, were dried and then heatedat 300 F. for 8 minutes.

The treated fabrics were tested for antistatic properties by allowingthe fabric to remain for 4 hours in an atmosphere having 33% relativehumidity. The fabrics Were then rubbed wth a wooden rod and held over anopen dish containing finely divided carbon at a distance of about 1 /2"or lower. If the carbon was not attracted to the fabric, the fabric wasconsidered to be antistatic.

6 The washes were carried out as described in Example II.

The results are shown in Table II.

Table II pH of pad bath: Antistatic durability, washes 7.0 10 9 5 20-30The example demonstrates the superior durability of the antistaticfinish when applied at a pH above 9.0.

While I have set forth certain specific examples and preferredembodiments of my invention, it will be understood that this is solelyfor purposes of illustration, and that various changes and modificationsmay be made in the invention without departing from the spirit of thedisclosure or the scope of the appended claims.

I claim:

1. A process for preparing a durable antistatic resin comprising (1)reacting at least a molar equivalent of a polyamine with a halohydrinether of a polyalkylene polyhydric alcohol at a temperature of fromabout to 135 C., to form a condensate and (2) reacting said condensatewith from about 5 to 25% N,N-methylenebis (acrylarnide) based on theweight of said condensate, at a temperature of from about 50 to C.

2. A process according to claim 1 in which said polyalkylene polyhydricalcohol is a polyethylene glycol.

3. A process according to claim 1 wherein said halohydrin isepichlorohydrin.

4. A process according to claim 1 wherein the amount ofN,N-methylenebis(acrylamide) is from about 5% to about 25% based on theweight of said condensate.

5. A process for imparting a durable antistatic finish to a synthetichydrophobic textile material which comprises applying an aqueoussolution of the resin produced by the process of claim 1 to said textileand thereafter drying said textile at elevated temperature.

6. A process according to claim 5 wherein the amount of resin applied tosaid textile is from about 0.25% to- References Cited UNITED STATESPATENTS 10/1963 Frotscher 11716l X 10/1964 Albrecht et al. 117-139.5

WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US.Cl. X.R.

